Manhole closure assembly with valve relief means

ABSTRACT

Manhole closure assembly primarily prevents drainage and storm water from emptying into manhole leading to sewerage system. Closure assembly comprises cover plate sealing off manhole opening. First valve is secured to cover plate for relieving pressure inside manhole when pressure therein exceeds predetermined amount, and second valve member is secured to cover plate for relieving vacuum inside manhole when vacuum therein exceeds predetermined amount.

United States Patent [191 Campagna 51 Jan. 23, 1973 [54] MANHOLE CLOSUREASSEMBLY WITH VALVE RELIEF MEANS [75] Inventor: Benjamin J. Campagna,Newark,

Del.

[73] Assignees: Benjamin J. Compagna, Newark; Eugene J. Truono,Wilmington, Del.

22 Filed: Nov. 13,1970

21 Appl.No.: 89,301

UNITED STATES PATENTS 2,518,533 8/1950 Kieber ..l37/493.8 1,685,7509/1928 Pfau et al. ....l37/493.8 1,099,073 6/1914 Moir ....l37/493.8

576,253 2/1897 Bingham ..94/37 579,864 3/1897 Moore et 31..... ....94/341,83 7,916 12/1931 Michelman ....94/34 3,308,727 3/1967 Hurt, Jr....94/34 2,009,132 7/1935 Gehris ..94/35 1,153,051 9/1915 Fairhurst..137/493.8

1,630,557 5/1927 Woodrow ..94/34 3,039,232 6/1962 Dunn .1 ..52/4952,599,622 7/1952 Folmsbee ..137/54l 507,636 10/1893 Schneider.....137/4938 3,267,631 8/1966 Hammitt ..52/495 3,192,671 7/1965 Smith..52/495 3,001,537 9/1961 Shepherd ....l37l533.29 3,288,167 11/1966Gibson ..137/541 144,844 11/1873 Campfield et a1. ..137/541 FQREIGNPATENTS OR APPLICATIONS 336,437 10/1930 GreatBritain ..94/34 PrimaryExaminer-Frank L. Abbott Assistant Examiner-Leslie A. BraunAtmmey-Connolly and Hutz ABSTRACT Manhole closure assembly primarilyprevents drainage and storm water from emptying into manhole leading tosewerage system. Closure assembly comprises cover plate sealing offmanhole opening. First valve is secured to cover'plate for relievingpressure inside manhole when pressure therein exceeds predeterminedamount, and second valve member is secured to cover plate for relievingvacuum inside manhole when vacuum therein exceeds predetermined amount.

4 Claims, 9 Drawing Figures PATENTEDJAH 23 I975 3,712,009

SHEET 3 [IF 3 MANHOLE CLOSURE ASSEMBLY WITH VALVE RELIEF MEANSBACKGROUND OF THE INVENTION The present invention relates to a manholeclosure assembly, and more particularly to a closure that preventsdrainage and storm water from emptying into a manhole that leads to asewerage system.

The primary reason for segregating sanitary or sewerage systems fromsystems designed to handle 1 storm and drainage water is an obvious one.Specifically, when drainage and storm water empties into a sanitarysystem the sewerage treatment plant must necessarily handle the stormwater in addition to the sewage material. These conditions place anunnecessary burden on the sewage treatment facility. Standard frames andcovers for manholes leading to sanitary or sewerage systems includecover constructions with passageways therein that enable storm water toempty into the sewerage system. The passageways in the standard coverconstructions are provided for relieving internal pressure in thesanitary system as well as preventing vacuum build-ups in the system. Itis impossible to simply plug up or otherwise eliminate the passagewaysin these covers since pressure developed inside the sanitary systemcould easily produce a force sufficient to blow the cover away from itsseated position at the manhole opening. Also, unrelieved vacuum can alsocause damage to the sanitary systems.

With an over designed sewerage system and/or an over capacity seweragetreatment plant, storm water draining into the sewerage system does notpresent any significant problems. However, with many systems capacity isnow 100 percent, and 40 percent of this capacity is the direct result ofstorm and drainage water. Storm water volume draining into seweragesystems is much more significant today than it was many years ago, andthe key factor is that today there is significantly less impervious areathan there was several years ago. This factor is due to larger streetareas that collect more drainage water as well as smaller building lotswhich cut down on the amount of overall impervious area. These factorshave significantly contributed to the problem of overtaxing presentsanitary systems. By significantly preve'nting storm and drainage waterfrom emptying into sanitary and sewerage systems, existing systems caneasily handle an additional 60 percent sewerage capacity.

SUMMARY OF THE INVENTION It is an object of the present invention toprovide a manhole closure assembly that effectively and easily seals offa manhole opening in an efficient and highly economical manner tothereby prevent drainage and stem water from emptying into the manhole.

Another object of the present invention is to provide a highly efficientand easy to follow method for preventing drainage and storm water fromemptying into a manhole.

In accordance with the present invention a manhole closure assembly isprovided for primarily preventing drainage and storm water from emptyinginto a manhole opening covered by the closure. The closure assemblycomprises a cover plate sealing off the manhole opening with a firstvalve member secured to the plate arranged to relieve pressure insidethe manhole when the pressure therein exceeds a predetermined amount. Asecond valve member also secured to the plate is arranged to relievevacuum inside the manhole when the vacuum therein exceeds apredetermined amount.

In one embodiment of the present invention the cover plate comprises apair of semicircular segments, and a connector strip seals and connectsthe semicircular segments together along their diametral edges.Preferably, the connector strip has a substantially I- shaped crosssection. One valve member is secured to one of the semicircular segmentsof the cover plate while the other valve member is secured to the secondsemicircular segment of the plate.

In another aspect of the present invention the manhole closure is incombination with an annular manhole frame surrounding the upper portionof the manhole and anchored thereto. The annular manhole frame has aninternal inwardly directed flange that supports the cover plate insealing relationship over the manhole opening by engaging the arcuateedges of the semicircular segmentsof the cover plate and the ends of theconnector strip. Sealing material is between the in wardly directedsupporting flange of the manhole frame and the arcuate edges of thesemicircular segments of the cover plate.

Preferably, the valve members of the present invention each comprise astationary valve body having at least one passageway therein thatprovides communication between the up side and down side of the coverplate when the valve member is open. Each passageway has a taper withthe upper open end thereof smaller than the lower open end thereof.Specifically, each valve member includes a valve body with a seatportion, a movable valve element and stem, and a biasing device betweenthe valve stem and the valve body normally urging the valve elementagainst the seat portion of the valve body. The valve element remainsseated until the force acting upon the movable valve element in thedirection opposite the force generated by the biasing device is greaterthan the force of the biasing device. When this condition occurs themovable valve element moves away from the seat portion of the valve bodyto open the valve member. In one valve member of the present inventionthe seat portion includes a substantially circular sharpened edge thatengages the movable valve element. A ring of resilient material iscarried by the movable valve element, and the ring is adapted to beengaged by the sharpened edge of the valvebody when the valve member isclosed.-

The cover plate may comprise a one piece circular segment with a pair ofspaced apart housings fixed to the underside thereof. The valve membersare secured to the housings with one valve member associated with eachhousing. Passageways are located in the cover plate directly over eachhousing for providing communication between the up side of the coverplate and the interior of the housings.

BRIEF DESCRIPTION OF THE DRAWING Novel features and advantages of thepresent invention in addition to those mentioned above will become FIG.2 is a sectional view taken along line 22 of FIG. 1;

FIG. 3 is a top plan view of another embodiment of the presentinvention;

FIG. 4 is a sectional view taken along line 4-4 of FIG. 3;

FIG. 5 is a side elevational view of a valve member according to thepresent invention;

FIG. 6 is a bottom plan view of the valve member shown in FIG. 5;

FIG. 7 is a sectional view taken along line 7-7 of FIG. 6 with the valvemember in its open position;

FIG. 8 is a side elevational view of another valve member according tothe present invention with portions broken away to show detail and withthe movable valve element shown in its unseated position inphantomoutline; and

FIG. 9 is a bottom plan view of the valve member shown in FIG. 8.

DETAILED DESCRIPTION OF THE INVENTION Referring in more particularity tothe drawing, FIGS. 1 and 2 illustrate a manhole closure assembly 10 forprimarily preventing drainage and storm water from emptying into amanhole 12 that leads to a sewerage system. As is well known, the upperend of most manhole constructions is surrounded by an annular manholeframe 14 embedded in a road bed 16 or similar surface construction. Theannular manhole frame has an upper inwardly directed flange 18 forsupporting a standard manhole cover or lid (not shown). The manhole lidhas passageways therein, as is well known.

The manhole cover assembly 10 of the present invention comprises a coverplate 20 fabricated from rigid metal or similar material including apair of semicircular segments 22, 24 and a connector strip or bar 26that seals, supports and connects the semicircular segments togetheralong their diametral edges 28. The bar 26 may also be constructed ofrigid metal and has an I- shaped cross section. As shown in FIG. 2, theannular manhole frame 14 has a lower inwardly directed flange 30 thatsupports the arcuate edges 32 of the semicircular segments 22, 24 of thecover plate 20. The flange 30 also supports the ends 34 of the connectorstrip 26. The two piece construction of the cover plate 20 enables theplate to be easily positioned in sealing relationship over the manholeopening. Caulking or other suitable sealing material 36 is locatedbetween the flange 30 and the arcuate edges of the cover plate 20.Sealing material is also located at the juncture between the diametraledges 28 and the connector strip 26 to provide an air tight seal of thecover plate over the-manhole opening. The weight of. the manhole coverassembly is usually sufficient to hold it in place over the manholeopening. However, suitable fastening struc ture may be provided if amore positive hold down is desired.

A first or pressure relief valve member 38 is secured to thesemicircular segment 22 of the cover plate 20 for relieving internalpressure inside the manhole l2. Additionally, a second or vacuum reliefvalve 40 is secured to the semicircular segment 24 of the cover plate 20for relieving vacuum that develops inside the manhole 12. As explainedmore fully below in conjunction with the details of FIGS. 5-7, the valvemembers 38, 40 function to relieve pressure and vacuum inside themanhole l2 when the pressure therein exceeds a predeterminedamount, suchas, for example, five pounds per square inch above atmospheric pressure,and also to relieve vacuum in the manhole when it exceeds apredetermined amount, such as, for example, five pounds per square inchbelow atmospheric pressure.

FIGS. 3 and 4 illustrate another movable closure assembly 50 accordingto the present invention wherein a standardmanhole cover or lid 52 isslightly modified so as to carry a pressure relief valve member 54 and avacuum relief valve member 56. In this regard, a pair of annularhousings 58 are formed on the underside of the .cover 52 directly belowpassageways 60 formed in the cover 52. As is clear from FIGS. 3 and 4,the passageways 60 in the cover 52 provide communication between the upside of the cover 52 and the interior of the annular housings 58. Eachhousing is sealed off at its lower end by a disc 62 which carries one ofthe valve members. Suitable fasteners such as 64 are provided foranchoring each disc to its respective annular housing 58. The valvemembers 54, 56 function to relieve pressure and vacuum inside themanhole 12 when these variables exceed predetermined amounts. Thedetails of the valve members 54, 56 are explained below in conjunctionwith FIGS. 8 and 9. The manhole cover 52 functions as a cover plate forsealing off the manhole opening. Sealing material or a suitable gasket66 is located between the lower peripheral edge portion of the cover 52and the supporting flange 18 of the annular manhole frame 14. 7

Referring now to FIGS. 5-7, the details of the valve member 38 are shownit being understood that the vacuum relief valve member 40 issubstantially the same as valve 38 except that the vacuum valve 40 opensin a downward direction to relieve vacuum while the pressure valve 38moves in an upward direction to relieve pressure. The pressure valve 38includes a stationary valve body 70 fabricated from aluminum, forexample, having a valve seat portion 72. The valve body 70 is securedto-the cover plate 20 by a locking ring arrangement 73. The valve 38also includes a movable valve element 74 and valve stem 76, and a coilspring 78 that reacts between the valve stem and the stationary valvebody 70. Passageways 80 are located in the valve body for providingcommunication between the up side and down side of the cover plate 20when the valve is open. The passageways 80 in' the pressure relief valve38 are tapered with an increasing cross sectional area in the downwarddirection. The tapered passageways provide a self-cleaning function, asexplained more fully blow. The movable valve element 74 carries a ringof resilient material 82 which engages the seat portion 72 of the valvebody 70 when the valve member is closed. As shown best in FIG. 7, thevalve seat portion 72 has a circular sharpened edge 84 that provides anair tight seal with the resilient ring 82 carried by the movable valveelement 74 when the valve is closed. Additionally, slit or othermaterial usually accumulates on top of the cover plate 20 and may reacha height close to the height of the valve seat 72. In such instances thesharpened edge 84 cuts through the silt to effectively close the valvewhen closure of the valve is desired.

Coil spring 78 is designed to hold the movable valve element 74 againstthe stationary valve body until the force acting upon the underside ofthe movable valve element is greater than the force of the coil spring78 which acts in an opposite direction. Thus, when the pressure insidethe manhole l2 exceeds 5 pounds per square inch, for example, the forcegenerated by that pressure on the movable valve element 74 is sufficientto urge the valve element in an upward direction to thereby relieve thepressure inside the manhole. When the valve opens water, slit, and silt,foreign material which accumulates on top of the cover plate is flushedthrough the passageways 80 before the valve 38 closes. The taperedconfiguration of the passageways 80 functions to assist in maintainingthem free of obstructions.

As mentioned above, the vacuum relief valve 40 is practically identicalto the pressure relief valve 38 except for its orientation.Additionally, the passageways in the stationary valve body of the vacuumrelief valve 40 are tapered in an opposite direction relative to themovable valve element 74. Thus, the vacuum relief valve 40 has the sameself-cleaning characteristics as the pressure relief valve even thoughthe vacuum valve is oriented so that the movable valve element 74 is onthe down side of the cover plate 20. When the downward pull on theexterior of the movable valve element 74 of the vacuum relief valve 40exceeds the force generated by the coil spring 78, the valve is pulledopen to thereby relieve the vacuum generated inside the manhole 12. Whenthe force of the coil spring exceeds the downward pull on the movablevalve element 74 the vacuum relief valve is snapped closed.

The valve members 54, 56 associated with the embodiment of the inventionspecifically illustrated in FIGS. 3 and 4, are shown in detail in FIGS.8 and 9. In the manhole closure assembly 50, the pressure relief valve54 is identical to the vacuum relief valve 56 except that the movablevalve element of the pressure relief valve moves in an upward directionwhen the valve is opened while the valve element of the vacuum reliefvalve moves in a downward direction when the valve is opened. The valve54 includes a stationary valve body 90 secured to the disc 62 of thecover plate assembly 50, as shown in FIG. 8. Sealing material 92provides an air tight seal between the body 90 and the disc 62.Passageways 94 are located in the body 90 for providing communicationbetween the up side and down side of the manhole closure assembly whenthe valve is opened. A movable valve element 96 secured to a valve stem98 moves away from the valve seat 100 of the body 90 when the force onthe lower surface of the valve element 96 is greater than the forcegenerated by the coil spring 102. As is clear, the coil spring 102reacts between a stationary spring seat 104'and the movable valve stem98. The movable valve element 96 carries a ring of resilient material106 that engages the seat 100 of the valve body when the valve isclosed.

Each of the embodiments of the present invention provides a manholeclosure assembly for sealing off the opening of a manhole constructionthat leads to a sewerage system. The closure prevents storm and drainagewater from emptying into the manhole. Excessive pressure inside themanhole is readily relieved when it exceeds a predetermined amount.Similarly, vacuum build-ups inside the manhole are relieved by asuitable vacuum relief.

What is claimed is:

l. The combination of a manhole closure assembly for preventing drainageand storm water from emptying into a manhole opening and an annularmanhole frame surrounding the upper portion of the manhole, the manholeframe including an upper lid supporting flange and a lower flange forsupporting the manhole closure assembly, and the closure assemblyincluding a cover plate supported by the'lower flange of the manholeframe in covering relationship over the manhole opening, the cover plateincluding a pair of substantially semicircular segments supported alongtheir arcuate edge portions by the lower flange of the manhole frame,means for connecting the semicircular segments together along theirdiametral edge portions, a first valve member secured to the cover plateconstructed and arranged to relieve pressure inside the manhole when thepressure therein exceeds a predetermined amount, and a second valvemember secured to the plate constructed and arranged to relieve vacuuminside the manhole when the vacuum therein exceeds a predeterminedamount.

2. The combination of claim 1 in which the first and second valvemembers each comprise a stationary valve body having at least onepassageway therein that provides communication between the up side anddown side of the cover plate when the valve member is open, and eachpassageway having a taper with the upper open end thereof smaller thanthe lower open end thereof.

3. The combination of claim 1 in which the uppermost ends of the firstand second valve members are elevated above the cover plate.

4. The combination of claim 1 in which the means for connecting thesemicircular segments together includes a connector strip supported atits ends by the lower flange of the manhole frame and securing thesemicircular segments together along their diametral edge portions.

# t: a r a:

1. The combination of a manhole closure assembly for preventing drainageand storm water from emptying into a manhole opening and an annularmanhole frame surrounding the upper portion of the manhole, the manholeframe including an upper lid supporting flange and a lower flange forsupporting the manhole closure assembly, and the closure assemblyincluding a cover plate supported by the lower flange of the manholeframe in covering relationship over the manhole opening, the cover plateincluding a pair of substantially semicircular segments supported alongtheir arcuate edge portions by the lower flange of the manhole frame,means for connecting the semicircular segments together along theirdiametral edge portions, a first valve member secured to the cover plateconstructed and arranged to relieve pressure inside the manhole when thepressure therein exceeds a predetermined amount, and a second valvemember secured to the plate constructed and arranged to relieve vacuuminside the manhole when the vacuum therein exceeds a predeterminedamount.
 2. The combination of claim 1 in which the first and secondvalve members each comprise a stationary valve body having at least onepassageway therein that provides communication between the up side anddown side of the cover plate when the valve member is open, and eachpassageway having a taper with the upper open end thereof smaller thanthe lower open end thereof.
 3. The combination of claim 1 in which theuppermost ends of the first and second valve members are elevated abovethe cover plate.
 4. The combination of claim 1 in which the means forconnecting the semicircular segments together includes a connector stripsupported at its ends by the lower flange of the manhole frame andsecuring the semicircular segments together along their diametral edgeportions.